Page 311 - UK Air Operations Regulations 201121

Part CAT - ANNEX IV - Commercial Air Transport Operations

(6) not more than 50 % of the reported headwind component or not less than 150 % of
the reported tailwind component.
CAT.POL.A.305 AMC1 Take-off
RUNWAY SURFACE CONDITION
(a) Unless otherwise specified in the AFM or other performance or operating manuals from
the manufacturer, the variables affecting the take-off performance and the associated
factors that should be applied to the AFM data are shown in Table 1 below. They should
be applied in addition to the operational factors as prescribed in CAT.POL.A.305.
(b) The soil should be considered firm when there are wheel impressions but no rutting.
(c) When taking off on grass with a single-engined aeroplane, care should be taken to
assess the rate of acceleration and consequent distance increase.
(d) When making a rejected take-off on very short grass that is wet and with a firm subsoil,
the surface may be slippery, in which case the distances may increase significantly.

CAT.POL.A.305 AMC2 Take-off
RUNWAY SLOPE
Unless otherwise specified in the AFM, or other performance or operating manuals from the
manufacturer, the take-off distance should be increased by 5 % for each 1 % of upslope except that
correction factors for runways with slopes in excess of 2 % should only be applied when the operator
has demonstrated to the CAA that the necessary data in the AFM or the operations manual contain
the appropriated procedures and the crew is trained to take-off in runway with slopes in excess of 2
%.
CAT.POL.A.305 GM1 Take-off
RUNWAY SURFACE CONDITION
(a) Due to the inherent risks, operations from contaminated runways are inadvisable, and
should be avoided whenever possible. Therefore, it is advisable to delay the take-off until
the runway is cleared.
(b) Where this is impracticable, the commander should also consider the excess runway
length available including the criticality of the overrun area.
CAT.POL.A.310 Take-off obstacle clearance — multi-engined aeroplanes
(a) The take-off flight path of aeroplanes with two or more engines shall be determined in
such a way that the aeroplane clears all obstacles by a vertical distance of at least 50 ft,
or by a horizontal distance of at least 90 m plus 0,125 x D, where D is the horizontal
distance travelled by the aeroplane from the end of the TODA or the end of the take-off
distance if a turn is scheduled before the end of the TODA, except as provided in (b) and
(c). For aeroplanes with a wingspan of less than 60 m, a horizontal obstacle clearance of
half the aeroplane wingspan plus 60 m plus 0,125 x D may be used. It shall be assumed
that:
(1) the take-off flight path begins at a height of 50 ft above the surface at the end of the
take- off distance required by CAT.POL.A.305(b) and ends at a height of 1 500 ft
above the surface;
(2) the aeroplane is not banked before the aeroplane has reached a height of 50 ft
above the surface, and thereafter the angle of bank does not exceed 15°;
(3) failure of the critical engine occurs at the point on the all engine take-off flight path
where visual reference for the purpose of avoiding obstacles is expected to be lost;
(4) the gradient of the take-off flight path from 50 ft to the assumed engine failure height
is equal to the average all-engines gradient during climb and transition to the en-
route configuration, multiplied by a factor of 0,77; and
(5) the gradient of the take-off flight path from the height reached in accordance with
(a)(4) to the end of the take-off flight path is equal to the OEI en-route climb gradient
shown in the AFM.
(b) For cases where the intended flight path does not require track changes of more than
15°, the operator does not need to consider those obstacles that have a lateral distance
greater than:
(1) 300 m, if the flight is conducted under conditions allowing visual course guidance
navigation, or if navigational aids are available enabling the pilot to maintain the
intended flight path with the same accuracy; or
(2) 600 m, for flights under all other conditions.
(c) For cases where the intended flight path requires track changes of more than 15°, the
operator does not need to consider those obstacles that have a lateral distance greater
than:
(1) 600 m, for flights under conditions allowing visual course guidance navigation; or
(2) 900 m, for flights under all other conditions.
(d) When showing compliance with (a) to (c), the following shall be taken into account:
(1) the mass of the aeroplane at the commencement of the take-off run;
(2) the pressure altitude at the aerodrome;
(3) the ambient temperature at the aerodrome; and
(4) not more than 50 % of the reported headwind component or not less than 150 % of
20th November 2021 311 of 856